Polarization Control by Leaky Surface Acoustic Wave in Reverse-Proton-Exchanged LiNbO3 Optical Waveguide

概要

論文の詳細を見る
Polarization control of the optical guided wave in a new configuration using a reverse-proton-exchanged (RPE) LiNbO3 straight waveguide and a leaky surface acoustic wave (LSAW) which propagates perpendicular to the straight waveguide was proposed. First, the perturbation of the dielectric tensor was estimated by using coupled mode theory. When a Love-type SAW on a proton-exchanged layer/YX-LiNbO3 was assumed, comparable perturbations to those in conventional Bragg diffraction due to a Rayleigh wave were confirmed. Next, a sample device with an LSAW wavelength \Lambda of 136 μm was fabricated on YX-LiNbO3 using an RPE channel waveguide. It was found that the incident linearly polarized wave was rotated by -90° in addition to the inherent rotation due to the perturbation of the LSAW without adding the LSAW wavenumber vector to the propagation constant of the incident optical guided mode. The maximum conversion efficiencies for optical wavelengths of 633, 532, and 473 nm were 87, 43, and 40%, respectively. The measured response time of 280 ns was almost equivalent to the time required for the propagation of the LSAW through the interdigital transducer width.
2012-07-25